[yaml2obj/obj2yaml] - Add support for .stack_sizes sections.

.stack_sizes is a SHT_PROGBITS section that contains pairs of
<address (4/8 bytes), stack size (uleb128)>.

This patch teach tools to parse and dump it.

Differential revision: https://reviews.llvm.org/D67757

llvm-svn: 372762

2 files changed, 67 insertions, 8 deletions

diff --git a/llvm/lib/ObjectYAML/ELFEmitter.cpp b/llvm/lib/ObjectYAML/ELFEmitter.cpp
index 4584e3d73bd..c394763459d 100644
--- a/llvm/lib/ObjectYAML/ELFEmitter.cpp
+++ b/llvm/lib/ObjectYAML/ELFEmitter.cpp
@@ -19,6 +19,7 @@
 #include "llvm/ObjectYAML/ELFYAML.h"
 #include "llvm/ObjectYAML/yaml2obj.h"
 #include "llvm/Support/EndianStream.h"
+#include "llvm/Support/LEB128.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/WithColor.h"
 #include "llvm/Support/YAMLTraits.h"
@@ -167,6 +168,9 @@ template <class ELFT> class ELFState {
   void writeSectionContent(Elf_Shdr &SHeader,
                            const ELFYAML::DynamicSection &Section,
                            ContiguousBlobAccumulator &CBA);
+  void writeSectionContent(Elf_Shdr &SHeader,
+                           const ELFYAML::StackSizesSection &Section,
+                           ContiguousBlobAccumulator &CBA);
   ELFState(ELFYAML::Object &D, yaml::ErrorHandler EH);
 
 public:
@@ -411,6 +415,8 @@ void ELFState<ELFT>::initSectionHeaders(std::vector<Elf_Shdr> &SHeaders,
       writeSectionContent(SHeader, *S, CBA);
     } else if (auto S = dyn_cast<ELFYAML::VerdefSection>(Sec)) {
       writeSectionContent(SHeader, *S, CBA);
+    } else if (auto S = dyn_cast<ELFYAML::StackSizesSection>(Sec)) {
+      writeSectionContent(SHeader, *S, CBA);  
     } else {
       llvm_unreachable("Unknown section type");
     }
@@ -782,6 +788,26 @@ void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader,
 }
 
 template <class ELFT>
+void ELFState<ELFT>::writeSectionContent(
+    Elf_Shdr &SHeader, const ELFYAML::StackSizesSection &Section,
+    ContiguousBlobAccumulator &CBA) {
+  using uintX_t = typename ELFT::uint;
+  raw_ostream &OS =
+      CBA.getOSAndAlignedOffset(SHeader.sh_offset, SHeader.sh_addralign);
+
+  if (Section.Content) {
+    Section.Content->writeAsBinary(OS);
+    SHeader.sh_size = Section.Content->binary_size();
+    return;
+  }
+
+  for (const ELFYAML::StackSizeEntry &E : *Section.Entries) {
+    support::endian::write<uintX_t>(OS, E.Address, ELFT::TargetEndianness);
+    SHeader.sh_size += sizeof(uintX_t) + encodeULEB128(E.Size, OS);
+  }
+}
+
+template <class ELFT>
 void ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader,
                                          const ELFYAML::VerdefSection &Section,
                                          ContiguousBlobAccumulator &CBA) {
diff --git a/llvm/lib/ObjectYAML/ELFYAML.cpp b/llvm/lib/ObjectYAML/ELFYAML.cpp
index 161224b0bb7..af795f9732c 100644
--- a/llvm/lib/ObjectYAML/ELFYAML.cpp
+++ b/llvm/lib/ObjectYAML/ELFYAML.cpp
@@ -1017,6 +1017,12 @@ static void sectionMapping(IO &IO, ELFYAML::RawContentSection &Section) {
   IO.mapOptional("Info", Section.Info);
 }
 
+static void sectionMapping(IO &IO, ELFYAML::StackSizesSection &Section) {
+  commonSectionMapping(IO, Section);
+  IO.mapOptional("Content", Section.Content);
+  IO.mapOptional("Entries", Section.Entries);
+}
+
 static void sectionMapping(IO &IO, ELFYAML::NoBitsSection &Section) {
   commonSectionMapping(IO, Section);
   IO.mapOptional("Size", Section.Size, Hex64(0));
@@ -1142,20 +1148,40 @@ void MappingTraits<std::unique_ptr<ELFYAML::Section>>::mapping(
     sectionMapping(IO, *cast<ELFYAML::SymtabShndxSection>(Section.get()));
     break;
   default:
-    if (!IO.outputting())
-      Section.reset(new ELFYAML::RawContentSection());
-    sectionMapping(IO, *cast<ELFYAML::RawContentSection>(Section.get()));
+    if (!IO.outputting()) {
+      StringRef Name;
+      IO.mapOptional("Name", Name, StringRef());
+
+      if (ELFYAML::StackSizesSection::nameMatches(Name))
+        Section = std::make_unique<ELFYAML::StackSizesSection>();
+      else
+        Section = std::make_unique<ELFYAML::RawContentSection>();
+    }
+
+    if (auto S = dyn_cast<ELFYAML::RawContentSection>(Section.get()))
+      sectionMapping(IO, *S);
+    else
+      sectionMapping(IO, *cast<ELFYAML::StackSizesSection>(Section.get()));
   }
 }
 
 StringRef MappingTraits<std::unique_ptr<ELFYAML::Section>>::validate(
     IO &io, std::unique_ptr<ELFYAML::Section> &Section) {
-  const auto *RawSection = dyn_cast<ELFYAML::RawContentSection>(Section.get());
-  if (!RawSection)
+  if (const auto *RawSection =
+          dyn_cast<ELFYAML::RawContentSection>(Section.get())) {
+    if (RawSection->Size && RawSection->Content &&
+        (uint64_t)(*RawSection->Size) < RawSection->Content->binary_size())
+      return "Section size must be greater than or equal to the content size";
     return {};
-  if (RawSection->Size && RawSection->Content &&
-      (uint64_t)(*RawSection->Size) < RawSection->Content->binary_size())
-    return "Section size must be greater than or equal to the content size";
+  }
+
+  if (const auto *SS = dyn_cast<ELFYAML::StackSizesSection>(Section.get())) {
+    if (SS->Content && SS->Entries)
+      return ".stack_sizes: Content and Entries cannot be used together";
+    if (!SS->Content && !SS->Entries)
+      return ".stack_sizes: either Content or Entries tag must be specified";
+    return {};
+  }
   return {};
 }
 
@@ -1184,6 +1210,13 @@ struct NormalizedMips64RelType {
 
 } // end anonymous namespace
 
+void MappingTraits<ELFYAML::StackSizeEntry>::mapping(
+    IO &IO, ELFYAML::StackSizeEntry &E) {
+  assert(IO.getContext() && "The IO context is not initialized");
+  IO.mapOptional("Address", E.Address, Hex64(0));
+  IO.mapRequired("Size", E.Size);
+}
+
 void MappingTraits<ELFYAML::DynamicEntry>::mapping(IO &IO,
                                                    ELFYAML::DynamicEntry &Rel) {
   assert(IO.getContext() && "The IO context is not initialized");